[asterisk-users] Redirect a GSM call through Wifi to a SIP phone

[adamk at 3a.hu]

Hi,

On 11/1/2013 5:02 PM, A J Stiles wrote:
> You probably will have the most success with Android, because you are going to
> need well-documented Source Code to stand a chance of getting anywhere.  You
> will need an Open Source SIP client and the Source Code for the stock Android
> GSM telephony app.  You then will have to bodge the two together somehow .....
>

please correct me if I'm wrong, but if the above was possible, then 
also, current SIP softphone apps would be able to do

- conference calls with a mixture of GSM and SIP endpoints
- transfer calls from/to GSM to/from SIP

which as far as I know, none of the apps offer.  If I remember 
correctly, one of the softphone app programmers provided a reason why 
the above will never work: you can't access a GSM call from an app due 
to security reasons.

I'm not sure what percentage I'm right, but I'd strongly suggest a GSM 
gateway for the function either with ethernet and SIP support, or an FXO 
port.  Much easier project.

regards
Adam